Interlaboratory Comparisons & Proficiency Test

The implementation of accepted quality assurance practices to analytical chemistry is recognized as a prerequisite to producing data with known metrological qualities. Regardless of the target analyte or sample type, quality assurance and quality control are the cornerstones to analytical data validation. In addition to daily internal performance verifications via reference materials, a good quality assurance plan should include regular external performance evaluations for an independent assessment of analytical proficiency.

The goal of interlaboratory studies is to demonstrate that participating to interlaboratory comparisons (ILCs) and proficiency tests (PTs) leads to improved quality of analytical results. The results from ILCs or PTs are of crucial interest for laboratories as these provide clear information of its measurement capabilities. It would be pointed out that the participation is either voluntary or forced by external requirements (e.g. legal, accreditation, control bodies). MEL Interlaboratory Comparison (ILC) exercises and Proficiency Test (PT) schemes involve comparison of participant’s results with an assigned value, which usually is delivered as a consensus value from the overall population of test results.

For nearly forty years, MEL has conducted ILC exercises in association with different regional seas programmes, as well as with the global investigation of the pollution in the marine environmental programme. MEL conducts both regional and global IC exercises and PT for different matrix of marine environment. For regional studies, the participation is generally limited; the objective of such a study is to provide participants with information on their analytical proficiency. For the global studies, the subject material is often sent out to ~200 laboratories world-wide.

MEL organizes more than three IC and PT exercises annually, one each for radionuclide, organic and inorganic contaminants. The inorganic study includes also the determination of methylmercury.

On-going Interlaboratory comparisons